Locomotive Developments.

While the steam locomotive remains the principal agency of power on the railways of the world, the development of greater power for a given unit of fuel—and particularly improvement in the economic use of fuel at the higher speeds—is a matter of considerable moment to those who work the railways.

A great deal of quiet research is carried on by railway engineers who are ever trying to solve the enigma of the marked disparity between the latent and the developed power of the fuel used on steam locomotives, because in the solution of this problem lies one important factor of the possible triumph of the rail in its fight for transport supremacy.

The railways, however, do not bring out a new model yearly and advertise its many virtues with the flourish of trumpets to which the producers of road transport vehicles are addicted, a custom which induced one caustic commentator to declare that “the difference between this year's model and last year's is that the flex of the cigar lighter is one inch longer.”

The railway custom is, rather, to treat its technical improvements in locomotive design with professional reticence, and when the facts are eventually revealed, to dress them up in a maze of technical detail, with graphs and engineering formulae and mathematical calculations that make impossible reading for any but engineers.

The more spectacular developments in locomotive design and practice—stream-lining, speed records, and so on—are the things in which the public find their greatest interest. Hence it is likely that the work of M. AndréA Chapelon of the Paris-Orleans Railway in studying the work of existing locomotives for the purpose of improving their performance may pass unnoticed in the world of news. Up to the present, copies of a paper he contributed to the Société des IngéAnieurs Civils de France, do not appear to have reached New Zealand, but as it is evident that he has been able (to quote “The Railway Gazette”) to “double the power and efficiency of existing engines simply by careful attention to fundamental principles” his work deserves to be more fully known.

M. Chapelon's research also serves as a useful reminder of the value of careful attention to detail in other classes of work where improvements are possible.

The efficiency of rail-cars, for instance, in which experiment has shown that tractive effort may be saved by a close attention to weight, suggest that more might be possible along this line in train construction, thus lessening the demands upon the locomotive and enabling further modification in its design to suit the lighter type of train.

The very durability of railway equipment—with locomotives still giving good service at the age of fifty and over—is a disadvantage when any large-scale change is found to be desirable. The virtue of M. Chapelon's work, it seems, lies in the fact that he has not called for new locomotives. He has simply made certain modifications in old ones, modifications that have helped to recover lost energy—mainly modifications in cylinder and valve design—much in the same way as a modern surgeon helps a deranged human system to better health.

The knowledge gained from these observations and experiments will also doubtless prove of great value to the designers of new locomotives, and as fuel costs are a very material factor in the economics of railway transport, keen interest will be taken throughout the railway world in any further developments arising out of the careful researches of M. Chapelon.